Mat forming apparatus for fiber web forming machine

ABSTRACT

This machine includes a moving condenser and an undercarriage having a solid plate confronting a part of the perimeter of the condenser. The condenser may be a rotating foraminous screen, or an endless foraminous belt. There is a duct inside the condenser, through which air is sucked to draw fibers onto the screen, and an adjustable baffle for determining the effective area of this duct. Fibers are sucked into the space between the plate and condenser by the air flowing through the condenser and compacted into a web by the moving condenser. In one embodiment of the invention an air intake box and an adjustable flap increase the stripping action on the pins of an apron in a feed hopper to deliver fibers between the undercarriage and condenser. In this embodiment also means is provided for varying the throat opening of the air bridge which carries the fibers from this apron between undercarriage and condenser. In another embodiment of the invention, to control the mat thickness the undercarriage is bodily adjustable relative to the condenser which here is an endless screen belt.

United States Patent [1 1 Wood [111 3,744,091 1 July 10, 1973 MAT FORMING APPARATUS FOR FIBER WEB FORMING MACHINE Dennis E. Wood, Penfield, NY.

[73] Assignee: Curlator Corporation, Macedon,

[75] Inventor:

[22] Filed: Dec. 21, 1970 [21] Appl. No.: 99,736

[521 US. Cl. l9/l56.3, 19/89 [51] int. Cl D0lg 25/00 [58] Field of Search 19/88, 89, 155, 156-1564,

OTHER PUBLICATIONS Rando-Webber, Rando-Feeder Machines, Pages 3, 6 & 7, Bulletin No. 101, Received Pat. Office October, 1950.

Primary Examiner-Dorsey Newton Attorney-Shiesinger, Fitzsimmons & Shlesinger [57] ABSTRACT This machine includes a moving condenser and an undercarriage having a solid plate confronting a part of the perimeter of the condenser. The condenser may be a rotating foraminous screen, or an endless foraminous belt. There is a duct inside the condenser, through which air is sucked to draw fibers onto the screen, and an adjustable baffle for determining the effective area of this duct. Fibers are sucked into the space between the plate and condenser by the air flowing through the condenser and compacted into a web by the moving condenser. in one embodiment of the invention an air intake box and an adjustable flap increase the stripping action on the pins of an apron in a feed hopper to deliver flbers between the undercarriage and condenser. In this embodiment also means is provided for varying the throat opening of the air bridge which carries the fibers from this apron between undercarriage and condenser. ln another embodiment of the invention, to control the mat thickness the undercarriage is bodily adjustable relative to the condenser which here is an endless screen belt.

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NON

MAT FORMING APPARATUS FOR FIBER WEB FORMING MACHINE The present invention relates to apparatus for feeding fibrous material to carding machines, machines for forming random fiber webs, and the like. In one aspect, this machine constitutes an improvement over certain structural features of the machine illustrated in the Langden et al. U. S. Pat. No. 2,890,497, issued June 16, 1959. In another aspect it is an improvement over the machine disclosed in the Buresh et al. U.S. Pat. No. 2,744,294, issued May 8, 1956.

FIG. 12 of U.S. Pat. No. 2,890,497 in particular illus trates how an air bridge may be coupled to a hopper feed for fibers in order to form the fibers into a mat for delivery into a carding machine, a machine for forming random fiber webs, or a similar machine.

In the apparatus illustrated in FIG. 12 of this patent, the undercarriage 122 carries a plurality of rolls 102, I06, 103 which converge with reference to the periphery of the rotary condenser 85 was to compress and feed forward the mat formed between these rolls and the condenser.

In U.S. Pat. No. 2,744,294, the fiber feeder mechanism includes an endless flexible screen 31 and a plurality of rollers 25 which are positioned in the undercarriage 26 to converge toward the screen condenser 31' in the direction of feed to form the mat of fibers and feed it forward.

With both constructions it has been found in practice that a number of problems have developed. Difficulties have been encountered in maintaining the correct surface speed of these rolls when coupled with the complete drive system of the feeder and of the webbing machine, since it is required that a certain draft ratio be maintained between the various rolls to form a suitable feed mat. Moreover, different types of fibers or blends of fibers require that adjustments be made in these draft ratios, thereby making the units somewhat cumbersome. More importantly, when there is a reduced pressure flow (suction) at the condenser, large quantities of air are drawn between and around the undercarriage rolls which, in turn, reduces the available differential air pressure drop between the air bridge opening at the hopper end above the plate 110 (U.S. Pat. No. 2,890,497) and above plate 78 (U.S. Pat. No. 2,744,294) and that at the web forming part of the condenser.

One object of the present invention is to provide apparatus which will produce a much improved feed mat in both structure and regularity, regardless of the type of condenser used.

Another object of this invention is to provide a feeding mechanism having improved air flow characteristics.

Still another object of the invention is to eliminate unwanted air flow in the mat forming section of the feed mechanism and make the flow of air to the condenser originate from the air bridge opening, thereby greatly improving the amount of fiber available to construct the feed mat and also improving the quality of the mat construction itself.

A still further object of the invention is to provide a feed mechanism of the character described to effect improved feeding, higher output, and better web uniformity.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawings.

In the drawings:

FIG. I is a longitudinal vertical sectional view through a feeder mechanism embodying in it apparatus built according to one embodiment of this invention;

FIG. 2 is an enlarged fragmentary vertical sectional view illustrating the improved undercarriage construc tion of the present invention, and showing its relation to the web-forming machine;

FIG. 3 is a fragmentary bottom plan view further illustrating this improved undercarriage construction; and

FIG. 4 is a view with parts removed showing a modification of the invention in which the condenser is an endless screen belt.

In the following description parts, which are identical, or substantially identical with parts disclosed in U.S. Pat. No. 2,890,497, are designated by the same reference numerals as in that patent, while parts, which are identical or substantially identical with parts disclosed in U.S. Pat. No. 2,744,294, are designated by the same reference numerals as used in this latter patent only raised by 500; and reference can be made to these patents for more detailed descriptions of the construction, function, and operation of those parts.

Referring now to the drawings by numerals of reference, and first to FIGS. 1 to 3 inclusive, 25 denotes generally a hopper into which the textile or other stock material which is to be fed, is dumped. The hopper is supported upon rollers 22.

Mounted in the base of the hopper is an endless floor apron or conveyor belt 27 on which are secured a plu rality of preferably wooden slats 28. This conveyor belt is mounted to travel over pulleys 29 and 30 which are journalled in the frame of the hopper.

The floor apron or conveyor 27 carries the stock material from adjacent the opening 26 to an elevating apron or conveyor 40 which is an endless belt mounted to travel over pulleys 41 and 42. This apron is provided with a plurality of straps 44 in which are embedded pins 45. These pins are inclined in the direction of travel of the belt. The pins 45 pick up bunches of the stock material, which are carried to the elevating apron by the floor apron 27; and they carry these bunches upwardly toward the top of the hopper as the belt 40 travels upwardly.

Mounted in the upper portion of the hopper to cooperate with the elevating apron is a stripping apron 50. This apron is an endless belt which travels over pulleys 51 and 52. This stripping apron carries a plurality of straps 54 in which are embedded pins 55. The pins 55 extend outwardly substantially perpendicular to the apron. The purpose of this stripping apron is to reduce the tufts of material, which are carried upwardly by the pins 45 of the elevating apron, to a size suitable for use in the formation of a mat from which fibers can be combed to form a random fiber web, etc. This stripping apron also serves to remove excess material from the elevating apron and to return this material to the loading end of the hopper. The stripping apron removes excessive fiber from the pins 45 of the elevating apron 40, leaving only small bunches of tufts on the individual pins 45.

The drives to the three aprons may be the same as described in U.S. Pat. No. 2,890,497, and form no part of the present invention, and for that reason are not described here in detail.

The tufts carried by the pins 45 are stripped from these pins by suction. A suction fan, designated as a whole at 70, is mounted on top of the hopper 25. This fan is driven by a motor 72, also mounted on top of the hopper, through pulleys 73 and 74 and the connecting belt 75. The fan exhausts to atomsphere through outlet pipe 76. Its intake is through a conduit 77, the lower end of which is secured to a screen box 80.

Journaled in the screen box 80 is a rotary condenser 85. This condenser is of conventional construction; and in the embodiment shown comprises an outer foraminous screen 86 (FIG. 2), which is secured to gears (not shown) for rotating it to provide a surface on which fibers may be deposited. A duct 89 extends transversely diametrically through the condenser and is bounded by duct spacers 90 and 91. These duct spacers are secured at opposite ends to opposite sides of the screen box 80. Thus the duct 86 is fixed relative to the rotary condenser, and may form an extension of the duct 77, or, in the alternative, the duct spacers 90 and 91 may be omitted and the duct 77 may be connected at one or both ends of an air tube 92 (FIG. 1) which extends axially through the screen 85, and has an arcuate opening 93 therein for sucking air through the rotating foraminous screen 89 to cause deposit of fibers on successive portions of the screen as it passes the opening 93. Seals 94 at opposite ends of this opening concentrate the air and form a duct between the screen 85 and the arcuate plate 92.

Adjacent the condenser and below it is the undercarriage 100 which comprises two laterally-spaced plates 402 and 403 (FIGS. 2 and 3) that carry stub shafts 404 and 405, respectively, which support rolls 406 and 407, respectively. Also mounted in plates 402 and 403, respectively are screws 408 and 409, respectively, which carry other rolls 410 and 411, respectively.

The rolls 406, 407, 410, 41 I, serve to support a plate or table 414, made of sheet steel and having a special anti-stick finish of, for instance, polytetrafluorethylene type. This plate extends at its ends partly around the rolls 406, 407 and 410, 411, and is riveted or otherwise fastened thereto.

As disclosed in U.S. Pat. No. 2,890,497, the small tufts of fiber', which are picked up by the pins 44 of the elevating apron 40, would travel endlessly around with this apron unless removed by the action of the air flow across the space (known as the air bridge) between the elevating apron and the condenser. The suction produced by the fan 70 causes the air bridge to be filled with tufts of fiber which are compacted by this suction. This compacting of the fibers in the trumpet-like opening tends to shunt off flow of air into the condenser, thereby stopping flow of fiber tufts from the elevating apron to the air bridge simply because there is an insufficient air flow to cause stripping of the fiber tufts from the apron pins as the pins travel past the air bridge.

When the condenser screen 86 rotates, the feed mat formed between the condenser and the undercarriage is moved forward, thus opening again an area to receive fiber tufts. Thus fibers are drawn into the air bridge again. This action is immediate provided the air flow is of sufficient strangth to remove the tufts of fiber from the elevator apron pins.

With the forward movement of the fiber in the air bridge, the air flow induces tufts of fiber to be packed into the air bridge to make up the feed mat. Furthermore, at any point across its width where the mat being formed is thin, the air flows easier than through the thicker parts, and fiber is immediately pulled into the weak area to build it up. Thus, a mat of uniform thickness across its width and length is formed. The air bridge, in effect, measures the output of fiber on a volumetric basis.

The packing of fiber into the air bridge is dependent on the intensity of the suction due to operation of fan 70. To control the fiber tuft flow, the air bridge area has been made adjustable. To this end, the portion of the wall of the feed chamber adjacent the undercarriage is made in two parts 435, 436. Part 435 is pivoted by pintle 437 on the wall 438 of the hopper 25; and part 436 is pivoted by pintle 439 at the rear end of the undercarriage 100.

Two different positions of the plates 435, 436 are illustrated in FIG. 1. By lowering the plates, for instance, the throat opening is increased, and hence an increase in fiber tuft flow results. This is needed for high denier fibers which do not form such a dense feed mat as other fibers.

Further to improve the air flow for stripping fibers from the elevating apron 40, a louvered air intake box 445 (FIG. 1) is mounted on top of hopper 25. As shown by the arrows, this added air stream flows from the outside across the pins of apron 40 and lifts tufts of fibers off the pins and delivers them into the space between the undercarriage and the condenser screen 86. The air flow is more direct; and the stripping action is increased. An adjustable flap 446 pivoted at 447 in the air intake box permits control of the volume of air flowing from the air intake box to the air bridge. The roof of the hopper above roll 42 may be sinuously curved to direct the flow of the air from the air intake box.

A doffing roll 104, similar to the doffing roll 104 of I U.S. Pat. No. 2,890,497, is provided to doff the mat formed from the surface of condenser 85 and assist in feeding the mat to the web of the forming unit which may be a random fiber web forming machine, a card, a garnett, etc.

The doffing roll 104 is journaled in the side frames 402 and 403 on suitable bearings, and has a portion of reduced diameter at the right hand end as viewed in FIG. 3 which may carry a pulley or gear or other driving means for this roll. A spacer 416, which is secured at opposite ends to the side frames 402, 403 by screws 417, and the spacer 418, which is secured to the side frames by threaded studs 419, serve to space the side frames 402 and 403 from one another. A sponge rubber seal or mat 420 (FIG. 2), which is glued, or otherwise fastened on top of the side frames, serves to seal the table 414 to the side frames along opposite sides of the table.

A to guide 422, which has a tapered nose screen condenser. to guide the mat formed on the machine under the doffing roll 104 and onto the feed plate where it is fed by the auxiliary roll 424 and by the feed roll 152 over the nose 151 of the feed plate to the lickerin 155.

Secured by screws 431 (FIG. 2) to the condenser plate 91 is an adjustable flexible baffle 430. This flexible baffle further improves the air flow by varying the condenser aperture, as from x, for instance, to x2 so that the induced suction air velocity may be controlled. The flexible baffle 430 extends downward from the interior of the condenser and turns upward toward the fiber flow and extends partially along the circumference of the foraminous screen or metal outer skin of the condenser. The baffie may be adjusted by retracting or extending the flexible material by adjusting the screws 431 by which the baffie is fixed to the condenser along slots in the baffle. Thus, the desired air flow velocity and density of the web for a given capacity may be obtained to compensate for any size or texture of the fibrous material which is introduced into the air bridge.

If the fan 70 associated with the condenser is drawing air at a given capacity, the velocity of the air will depend upon the dimensions of the open area of the orifice through which the air is drawn. If the total orifice area is large the air will flow slowly through this opening, whereas if a smaller open area is exposed, the air will flow at a considerably higher rate. Thus, the density of the web may be varied; and the increased stripping of the fibrous material from the pins of the inclined apron is likewise increased since all the air is drawn into the air bridge from inside the feeder section and not as previously, through the openings around the rollers of the undercarriage. By using a solid undercarriage 414 this unwanted air How is eliminated; and the flow of air to the condenser originates from the air bridge opening thereby greatly improving the amount of fiber available to construct the feed mat and also improving on the quality of the mat itself, giving improved feeding, higher output and better web uniformity.

Referring now Jo FIG. 4, 531' denotes the endless screencondenser. This screen travels around the four rolls 530' which are journaled in the screen box 702. A suction tube 700 is mounted in the screen box 702 and is connected to a suction fan (not shown) mounted on the screen box. This tube has an opening at 704 through which it sucks air through the traveling condenser screen to .cause fibers to deposit on the screen.

The area of the screen opening is controlled by a flexible baffie 706 which is wound at one end on the roller 708, which may be like a curtain roller and which is journaled at opposite ends in the screen box. The free end of the baffie can be drawn down manually to any desired degree across the opening 704. It can be held in place by the weight of its weighted end 710, or by any suitable fastening means.

The undercarriage 712 has a solid upper surface 714, which confronts the lower reach of the screen belt 531'. Fibers may be fed to the space between the undercarriage and the lower reach of the screen belt from a hopper, similar to hopper 25 (FIG. 1), and by an elevating apron, similar to apron 40, and may be doffed from the elevating apron by suction as in the embodiment illustrated in FIG. 1. They are drawn, as denoted by the arrows in FIG. 4, through operation of the air bridge into the space between the undercarriage 712 and the lower reach of the screen belt 531.

The undercarriage is pivotally connected at one end to the hopper by pin 715. It is adjustable toward and from the screen belt through operation of a fluid pressure actuated ram 716 comprising the telescoping parts 718 720. The inner telescoping rod 720 is pivotally connected by pin 722 to the ear 724 which depends from the undercarriage 712. Bolts 726 which pass through slots in the side flanges 730 of the undercarriage serve to hold the undercarriage in any adjusted position.

Doffing rolls 734, 736, 738 doff the mat formed between the lower reach of the condenser 531' and the undercarriage plate 714 from the condenser and guide this mat to the feed plate of the machine whichmay be like plate 130 (FIG. 1). v,

From th preceding description it will be evident that the feed mechanism of the present invention creates a much improved fiber flow without extraneous diversions. Thus, the density and uniformity of the feed mat is improved, which, in turn, means an improved web formation in the web forming machine to which this feed mechanism is coupled. The adjustability of the cross-section of the air bridge allows more precise control of the size of the fiber tufts which make up the mat and which are delivered to the web-forming machine. It also permits adjustment of the weight of the feed mat to be formed. Upon comparison of the feed mat produced by the apparatus of this invention with webs such as produced by feed mechanism such as disclosed in the U. S. Pat. No. 2,890,497, the following data was obtained:

Two machines were run side by side using the same fiber, same weight of feed mat, same speeds of rotating parts, etc., In other words, both FEEDERS were operating in the same manner so that the only variation would be due to the air flow and the undercarriage differences: Test Fiber Coefficient of Variation of Feedmat U.S. P. 2890497 Improved type FEEDER FEEDER l 9.1% 8.8%

Cotton 1 1/32" SLM 2 Blend 50% Cotton 50% Avril Fiber 12.8% 11.1% 1% denier 1 /4" 3 100% Avril Fiber 6.8% 6.1%

It has also been found that the output of the improved FEEDER measured in pounds per hour is increased some four fold so that not only is the regularity of the feed mat improved, but the production of the equipment is substantially increased with improved uniformity not only in the width direction, but also in the long term variations which are particularly troublesome when the FEEDER is connected to a Card which is producing a high quality sliver.

While the invention has been described in connection with two specific embodiments thereof, it will be understood that it is capable of further modification, and that this application is intended to cover any variations, uses, or embodiments of the invention that come within the disclosure, or the limits of the appended claims.

Having thus described my invention, what I claim is:

l. A fiber feed mechanism comprising a hopper,

an elevating apron movably mounted in said hopper and carrying pins for picking up tufts of fibers from said hopper and carrying said tufts upwardly,

a movable foraminous condenser,

a solid, imperforate undercarriage confronting said condenser and spaced therefrom,

means for sucking air over pins on the ascending reach of said apron, during upward travel thereof, and into the space between said condenser and undercarriage and through said condenser to deliver fibers into said space and deposit them on said condenser, and

means for adjustably varying the area at the entering end of said space, said varying means comprising two cooperating plates, each pivoted at one end, and having their opposite ends overlapping, the pivotal axes of said two plates being spaced from one another. 2. a fiber feed mechanism comprising a hopper, an elevating apron movably mounted in said hopper and carrying pins for picking up tufts of fibers from said hopper and carrying said tufts upwardly, a movable forminous condenser, a solid, imperforate undercarriage confronting said condenser and spaced therefrom, means for sucking air over pins on the ascending reach of said apron, during upward travel thereof, and into the space between said condenser and undercarriage and through said condenser to deliver fibers into said space and deposit them on said condenser, and means for adjustably varying the area at the entering end of said space, an air intake box mounted on said hopper to deliver air from the outside to a point above said apron, whereby said sucking means draws air also from said box over the top of said apron and into the space between said condenser and said undercarriage, said condenser being an endless screen belt, said undercarriage confronting one reach of said belt, and being pivotal toward and from said one reach. 3. A fiber feed mechanism as claimed in claim 2, wherein a tube is mounted within said belt, and said means for sucking air is connected to said tube to suck air through an opening in said tube to cause fibers to be drawn into the space between said undercarriage and said one reach and onto said one reach. 4. A fiber feed mechanism as claimed in claim 3, wherein a flexible baffle is mounted on said tube to control the effective area of the opening in said tube. 5. A fiber feed mechanism as claimed in claim 4, wherein the last-named flexible baffle is a flexible curtain wound at one end around a rod which is external of said duct and positioned to be drawn over the opening in said duct.

6. A fiber feed mechanism comprising a hopper,

an upwardly inclined endless elevating apron movably mounted in said hopper and carrying pins for picking up tufts of fibers from said hopper and carrying said tufts upwardly,

a movable foraminate condenser,

a fixed, solid, imperforate arcuately curved undercarriage confronting said condenser and spaced therefrom and extending partway around said condenser,

a duct extending from the ascending reach of said apron under said condenser,

said condenser forming part of the upper wall of said duct,

means for sucking air over pins on the ascending reach of said apron, during upward travel thereof and over the top of said apron and into said duct in the space between said condenser and undercarriage and through said condenser to deliver fibers into said space and deposit them on said condenser, and

means adjacent said carriage forming another part of the lower wall of said duct, and

meansfor adjusting the latter part of said duct to vary the area at the entering end of said duct.

7. A fiber feed mechanism as claimed in claim 6,

wherein an air intake box is mounted on said hopper to deliver air from the outside,

an arcuate wall confronts the upper end of said elevating apron and forms the upper wall of a duct to receive air from said intake box and conduct this air across the pins when they attain their topmost position in the ascending reach of said apron, whereby said sucking means draws air also from said box over the top of said apron and into the space between said condenser and said undercarriage,

the lower wall of the last-named duct being formed in part by the upper end of said apron. 

1. A fiber feed mechanism comprising a hopper, an elevating apron movably mounted in said hopper and carrying pins for picking up tufts of fibers from said hopper and carrying said tufts upwardly, a movable foraminous condenser, a solid, imperforate undercarriage confronting said condenser and spaced therefrom, means for sucking air over pins on the ascending reach of said apron, during upward travel thereof, and into the space between said condenser and undercarriage and through said condenser to deliver fibers into said space and deposit them on said condenser, and means for adjustably varying the area at the entering end of said space, said varying means comprising two cooperating plates, each pivoted at one end, and having their opposite ends overlapping, the pivotal axes of said two plates being spaced from one another.
 2. a fiber feed mechanism comprising a hopper, an elevating apron movably mounted in said hopper and carrying pins for picking up tufts of fibers from said hopper and carrying said tufts upwardly, a movable foraminous condenser, a solid, imperforate undercarriage confronting said condenser and spaced therefrom, means for sucking air over pins on the ascending reach of said apron, during upward travel thereof, and into the space between said condenser and undercarriage and through said condenser to deliver fibers into said space and deposit them on said condenser, and means for adjustably varying the area at the entering end of said space, an air intake box mounted on said hopper to deliver air from the outside to a point above said apron, whereby said sucking means draws air also from said box over the top of said apron and into the space between said condenser and said undercarriage, said condenser being an endless screen belt, said undercarriage confronting one reach of said belt, and being pivotal toward and from said one reach.
 3. A fiber feed mechanism as claimed in claim 2, wherein a tube is mounted within said belt, and said means for sucking air is connected to said tube to suck air through an opening in said tube to cause fibers to be drawn into the space between said undercarriage and said one reach and onto said one reach.
 4. A fiber feed mechanism as claimed in claim 3, wherein a flexible bafflE is mounted on said tube to control the effective area of the opening in said tube.
 5. A fiber feed mechanism as claimed in claim 4, wherein the last-named flexible baffle is a flexible curtain wound at one end around a rod which is external of said duct and positioned to be drawn over the opening in said duct.
 6. A fiber feed mechanism comprising a hopper, an upwardly inclined endless elevating apron movably mounted in said hopper and carrying pins for picking up tufts of fibers from said hopper and carrying said tufts upwardly, a movable foraminate condenser, a fixed, solid, imperforate arcuately curved undercarriage confronting said condenser and spaced therefrom and extending partway around said condenser, a duct extending from the ascending reach of said apron under said condenser, said condenser forming part of the upper wall of said duct, means for sucking air over pins on the ascending reach of said apron, during upward travel thereof and over the top of said apron and into said duct in the space between said condenser and undercarriage and through said condenser to deliver fibers into said space and deposit them on said condenser, and means adjacent said carriage forming another part of the lower wall of said duct, and means for adjusting the latter part of said duct to vary the area at the entering end of said duct.
 7. A fiber feed mechanism as claimed in claim 6, wherein an air intake box is mounted on said hopper to deliver air from the outside, an arcuate wall confronts the upper end of said elevating apron and forms the upper wall of a duct to receive air from said intake box and conduct this air across the pins when they attain their topmost position in the ascending reach of said apron, whereby said sucking means draws air also from said box over the top of said apron and into the space between said condenser and said undercarriage, the lower wall of the last-named duct being formed in part by the upper end of said apron. 